Emergency Procedures & Accident Prevention Flashcards

During a critical lift, the crane's load line suddenly develops a visible kink just above the hook block. The load is suspended 40 feet in the air with workers below. What is the CORRECT immediate action sequence?

Answer: Stop all movement immediately, alert all personnel to clear the area, then slowly lower the load to the ground using the minimum speed setting before shutting down

A kinked wire rope has compromised structural integrity and can fail without warning. All movement must stop immediately to prevent additional stress on the damaged area. Personnel must clear the area before any controlled lowering begins. Lowering slowly at minimum speed reduces dynamic loading on the kinked section. Increasing speed (B) increases shock loading risk. Adding a secondary sling (C) requires additional movement and time with a compromised line. Swinging the boom (D) introduces lateral stress on the already-weakened line.

A crane operator is conducting a pick near an energized 69 kV overhead power line. The job briefing established a 15-foot work zone buffer. Mid-lift, the signal person indicates the load must travel 3 feet closer to the line than planned. The new path would maintain 13 feet of clearance. The operator should:

Answer: Refuse the lift along the new path, since OSHA 1926.1408 requires a minimum 20-foot clearance for lines over 50 kV, which the new clearance violates

OSHA 29 CFR 1926.1408 Table A specifies that for lines over 50 kV (which 69 kV exceeds), the minimum clearance is 10 feet PLUS 0.4 inches per kV above 50 kV, which for 69 kV equals approximately 20.6 feet — not a flat 10 feet. The established 15-foot buffer already violated this requirement; 13 feet compounds the violation. The signal person's verbal confirmation (C) has no authority to override OSHA minimums. Option D describes a valid administrative control but still cannot authorize proceeding below the legal clearance.

An operator notices the anti-two-block (ATB) warning device is activating intermittently with no apparent load change. After inspection, no physical obstruction is found near the two-block limit switch. What does this MOST LIKELY indicate, and what is the correct action?

Answer: The ATB system has a wiring or sensor fault; tag out the crane and remove it from service until the device is inspected and repaired by a qualified person

An ATB device that activates without apparent cause indicates a system malfunction — the device cannot be trusted to reliably warn of an actual two-blocking event. ASME B30.5 and OSHA 1926.1416 require that malfunctioning safety devices result in the crane being removed from service until repaired by a qualified person. Using a manual spotter (B) is not an OSHA-approved substitute for a required safety device. Attributing it to load swing (C) is speculative and does not address a potential sensor failure. Using the bypass switch (D) is only permitted for specific, controlled maneuvers as defined by the manufacturer — not as a workaround for a malfunctioning device.

During a tandem lift using two mobile cranes, Crane A's operator receives a hand signal to hoist while Crane B's operator receives a simultaneous signal to lower from two different signal persons. The load is at mid-pick. What is the MOST critical error in this scenario, and what should both operators do?

Answer: The error is having two signal persons; ASME B30.5 requires one designated lead signal person for tandem lifts — both operators should stop all movement immediately

ASME B30.5 and the NCCCO standards require that tandem crane lifts have a single designated signal person who directs both operators simultaneously. Two separate signal persons giving conflicting commands is a fundamental procedural violation that creates uncontrolled load geometry — one crane hoisting while the other lowers can cause one crane to become overloaded as load shifts, potentially causing tipping or structural failure. The correct response for both operators is to immediately stop all motion upon recognizing the conflict. Defaulting to hoisting (B) transfers full load to one crane. Crane A continuing (C) perpetuates the split-authority violation. Lowering immediately (D) under conflicting control is as dangerous as any other movement.

A crane operator is conducting a pick in gusty conditions. The wind speed averages 18 mph but gusts reach 27 mph. The crane's load chart wind limit is 20 mph. The lift director states the average wind is within limits and instructs the operator to proceed. The operator should:

Answer: Refuse the lift, because peak gust speed — not average wind speed — determines whether wind conditions exceed safe operating limits for crane operations

Wind loading on a suspended load is governed by peak gust forces, not average wind speed. A 27 mph gust creates approximately 2.25 times the force of an 18 mph average wind (force scales with the square of velocity: 27²/18² ≈ 2.25). Crane load charts that specify wind limits are based on sustained/peak conditions, and gusts that exceed the manufacturer's stated limit make the lift unsafe regardless of the average. ASME B30.5 places the authority to stop operations due to unsafe conditions with the operator — not the lift director. Tag lines (C) do not reduce wind force on the load or the crane structure. The site safety officer (D) cannot override a manufacturer wind limit.

While lowering a load into a confined excavation, the operator loses sight of the load and the designated signal person. The operator has not received a stop signal. Under NCCCO/OSHA standards, what must the operator do?

Answer: Stop all crane movement immediately and not resume until the signal person reestablishes visual contact and communication with the operator

OSHA 29 CFR 1926.1419(a) explicitly states that if an operator loses sight of the load or the signal person and no stop signal has been received, the operator must stop all movement. This is an unconditional requirement — the absence of a signal is NOT a continuation signal. Continuing at reduced speed (B) violates this rule. Self-direction using sound (C) is not permitted under OSHA standards, which require a qualified signal person with established communication. Lowering to the bottom (D) introduces movement into an unseen zone where workers, equipment, or obstructions may be present — the excavation context makes this especially dangerous.